Using GCxGC to understand decomposition odour in Canadian environment (Rushali Dargan, MDCW 2023)

• 🎤 Presenter: Rushali Dargan, Benoit Daoust, Shari Forbes (Université du Québec à Trois-Rivières, Trois-Rivières, Canada)

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Abstract

Human decomposition odour is comprised of volatile organic compounds (VOCs) released during the process of decomposition. Decomposition is inherently governed by the environment in which it occurs thus, results from one environment type cannot be extrapolated to another. This study was the first human decomposition study to be conducted in the humid continental climate of Québec, Canada. VOCs were collected from the headspace of eight cadavers decomposing in an outdoor scenario at Canada’s first human taphonomic research facility.

Air samples were collected on sorbent tubes and analysed with comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (GC×GC-TOFMS). The results indicated that compounds belonging to previously reported chemical classes such as acids, alcohols, aldehydes, aromatics, cyclic aliphatics, esters and analogues, ethers, halogen-containing, ketones, linear aliphatics, nitrogen-containing, and sulphur-containing VOCs were identified.

This study presents a list of prominent (recurring) VOCs that are evolved during human decomposition. Identifying these VOCs is significant because, during their searches for human remains, cadaver detecting dogs (CDDs) might be potentially associating these with their target odour. A knowledge of which VOCs are decomposition-related is a crucial first step to improving their training and hence the outcome of CDD searches.

Additionally, this study also found differences in VOC profile owing to variation in average ambient temperature resulting from the rapid progression of decomposition during warmer ambient temperatures. The VOC profile during the active and bloat stage was found to be the most variable compared to the fresh and late decomposition stages.